For quite some time, I think the tire codes have been on the tires, so it is a good thing for the owner to check the tires themselves.  They can go by the dates, but more importantly, they need to be looking for tread wear, weather checking, cuts and bulges.  We once bought a brand new car and about the time it was three years old, one of the tires went bad when Jo was on a trip all the way from western Kansas to eastern Kansas.  An attendant at the service station in either Dodge City or Great Bend noticed the tire as she was driving out and stopped her.  They all got to looking at all the tires then and every one of them were in bad shape.  I had her replace all four right then and there.

My issue with requiring inspections mandated by the states is that the inspectors aren't always knowledgeable about tires and what to look for to determine a bad tire.  Unless there is something like an x-ray or some other device to check the tires with, I suspect a lot of bad tires would still be on the road.  And, how many inspectors are going to want to buy an expensive device for "scanning" tires when they probably only get a couple of dollars for each inspection?

Terry